pratt



(No Model.)

A.'K. PRATT.

LODM.

No. 577,692. Patented Feb-28, 1897.

IIIIIIIIIHHIII ll [H WZ'Z'NIEE'EE. INYZNTUE:

NITED STATES PATENT OFFICE.

ALBERT K. PRATT, OF NORTHBRIDGE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO FRANK S. BERRY, OF SAME PLACE.

LOOM.

SPECIFICATION forming part of Letters Patent No. 577,692, dated February 23, 1897. Application filed February 26, 1896. Serial No, 580,836. (No model.)

To all whom it-mwy cancer-n.-

Be it known that I, ALBERT KENNEDY PRATT, of Northbridge, in the county of Worcester and State of Massachusetts, have invented a new and useful Improvement in Looms; and I hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification. 1

IVhen in a loom the warpthreads are sprung by the heddles upward and downward to form the shed, a sudden strain is brought on the warp-threads, and when the warpthreads are brought to the horizontal line in crossing they slack. The whip-rod has been arranged to yield to excessive strain on the Warp-threads, but in practice it is found that warp-threads frequently break from the sudden strain of the heddles which would not have broken if the warp-beam had yielded to extra strain and taken up the slack.

The object of this invention is to give to the warp-beam the capacity to yield to this extra strain on the warp-threads and automatically take up the slack.

The invention consists in the peculiar and novel construction and combination of the parts, as will be more fully set forth hereinafter, and more particularly pointed out in the claims.

Figure 1 is a side view of the rear end of the loom, showing the let-oif motion and its connection with the pinion-shaft, by which the warp-beam is operated. Fig. 2 is an end view of part of a loom, showing the warpbeam and the pinion-shaft. Fig. 3 is a sectional View showing the worm-gear mounted loose on the pinion-shaft and connected bya coiled spring with a collar secured tothe pinion-shaft.

In the drawings I have shown the preferred form in which I carry out my invention; but I do not wish to confine myself to the exact construction shown.

Similar numerals of reference indicate corresponding parts in all the figures.

worm 7 is secured, and this worm engages with the worm-gear 8, which has heretofore been secured to the pinion-shaft 9, but which I now mount loose on the shaft. The wormgear 8 is secured to the spiral spring 10, surrounding the pinion-shaft 9. The opposite end of the spiral spring 10 is secured to the collar 11, which is secured to the pinion-shaft 9,.adjustably by means of a clamp-screw, so that in place of the former rigid connection with the shaft the worm-gear 8 is now connected yieldingly by the coiled spring 10 with the shaft 9. The pinion 12 on the pinionshaft 9 engages with the gear 13, secured to and turning with the warp-beam 14:. All the parts are supported in their usual bearings, and the operation of the parts remain practically the same as heretofore with the exception that any excessive strain on the warp is transmitted to the pinion-shaft and the coiled spring 10, and any slack in the warp is taken up again by the reaction of the coiled spring acting on the pinion-shaft and through the pinion 12 and gear 13 on the warp-beam.

The worm-gear S is held in the required position by suitable collars against longitudinal movement on the shaft by the torsion on the coiled spring 10.

By applying the coiled spring so as to exert the torsional spring action on the pinionshaft a powerful strain is applied to the warp by a comparatively small spring, because the spring strain is multiplied by the small pinion 12, which engages with the large gear on the warp-beam, and thus the 1et-off of the warp, is more perfectly controlled.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. In a loom, the combination with the Warp-beam connected to the pinion-shaft by means of gears, of the pinion-shaft, a wormgear loose on the same, a coiled spring, surrounding the shaft, secured at one end. to the shaft by an adjustable collar and at the other end to the loose worm-gear, and means for turning the loose worm-gear; whereby a yielding adjustable spring strain is exerted on the warp and slack warp or excessive sudden strain on the yarn is avoided, as described.

2. In a "loom, the combination with the ICO Warp-beam, the gear connected therewith, beam and on the warp and the slack is taken 10 and the shaft carrying the pinion-gear engagup, as described.

ing with the gear on the warp-beam, of a gear In witness whereof I have hereunto set my loose on the shaft, and a coiled spring incloshand.

5 ing the shaft, one end of said spring being secured to the shaft and the other end to the ALBERT PRAT'I' loose gear, means for turning the loose gear WVitnesses: whereby the torsional strain of the coiled JOSEPH A. MILLER, J r., spring is exerted on the gear of the warp- M. F. BLIGH. 

